Superconductivity and Charge Density Wave in ZrTe3−x_{3-x}Sex_{x}

Charge density wave (CDW), the periodic modulation of the electronic charge density, will open a gap on the Fermi surface that commonly leads to decreased or vanishing conductivity. On the other hand superconductivity, a commonly believed competing order, features a Fermi surface gap that results in infinite conductivity. Here we report that superconductivity emerges upon Se doping in CDW conductor ZrTe$_{3}$ when the long range CDW order is gradually suppressed. Superconducting critical temperature $T_c(x)$ in ZrTe$_{3-x}$Se$_x$ (${0\leq}x\leq0.1$) increases up to 4 K plateau for $0.04$$\leq$$x$$\leq$$0.07$. Further increase in Se content results in diminishing $T_{c}$ and filametary superconductivity. The CDW modes from Raman spectra are observed in $x$ = 0.04 and 0.1 crystals, where signature of ZrTe$_{3}$ CDW order in resistivity vanishes. The electronic-scattering for high $T_{c}$ crystals is dominated by local CDW fluctuations at high temperures, the resistivity is linear up to highest measured $T=300K$ and contributes to substantial in-plane anisotropy.Comment: 15 pages, 4 figure

Hadoop distributed file system for the Grid

Data distribution, storage and access are essential to CPU-intensive and data-intensive high performance Grid computing. A newly emerged file system, Hadoop distributed file system (HDFS), is deployed and tested within the Open Science Grid (OSG) middleware stack. Efforts have been taken to integrate HDFS with other Grid tools to build a complete service framework for the Storage Element (SE). Scalability tests show that sustained high inter-DataNode data transfer can be achieved for the cluster fully loaded with data-processing jobs. The WAN transfer to HDFS supported by BeStMan and tuned GridFTP servers shows large scalability and robustness of the system. The hadoop client can be deployed at interactive machines to support remote data access. The ability to automatically replicate precious data is especially important for computing sites, which is demonstrated at the Large Hadron Collider (LHC) computing centers. The simplicity of operations of HDFS-based SE significantly reduces the cost of ownership of Petabyte scale data storage over alternative solutions

Discutindo a educação ambiental no cotidiano escolar: desenvolvimento de projetos na escola formação inicial e continuada de professores

A presente pesquisa buscou discutir como a Educação Ambiental (EA) vem sendo trabalhada, no Ensino Fundamental e como os docentes desta escola compreendem e vem inserindo a EA no cotidiano escolar., em uma escola estadual do município de Tangará da Serra/MT, Brasil. Para tanto, realizou-se entrevistas com os professores que fazem parte de um projeto interdisciplinar de EA na escola pesquisada. Verificou-se que o projeto da escola não vem conseguindo alcançar os objetivos propostos por: desconhecimento do mesmo, pelos professores; formação deficiente dos professores, não entendimento da EA como processo de ensino-aprendizagem, falta de recursos didáticos, planejamento inadequado das atividades. A partir dessa constatação, procurou-se debater a impossibilidade de tratar do tema fora do trabalho interdisciplinar, bem como, e principalmente, a importância de um estudo mais aprofundado de EA, vinculando teoria e prática, tanto na formação docente, como em projetos escolares, a fim de fugir do tradicional vínculo “EA e ecologia, lixo e horta”.Facultad de Humanidades y Ciencias de la Educació

Reconstruction of missing transverse energy and prospect of searching for Higgs boson produced via vector boson fusion in Compact Muon Solenoid experiment

We performed full detector simulation studies of missing transverse energy (Emiss T ) reconstruction and correction, and the prospects for searching for a low mass Higgs Boson (120 < mH < 250 GeV/c 2 ) produced via the vector boson fusion (VBF) process through the decay of H → W+W− → `νjj at Compact Muon Solenoid (CMS) experiment in Large Hadron Collider (LHC). We developed a new jet energy correction algorithm by parameterizing the jet energy distribution around the jet axis. The jet energy resolution is improved by calibrating the jet energy scale and by reducing the variance of the measurement error. Correction functions showed good performance in restoring the jet transverse momentum (pT) spectrum. The methods provide a good framework to study jet quantities and optimize jet reconstruction and correction techniques. We evaluated the performance of the CMS detector for measuring the Emiss T using QCD events. We also studied the contributions from detector resolution, minimum bias pileup, event topology, tower energy thresholds and the exclusion of the unclustered region in the calorimeter. We built a comprehensive strategy for the Emiss T correction for leptonic events. The performance as applied to t¯t and W+jets events showed improved the Emiss T resolution, the azimuthal (φ) resolution and average Emiss T scale. Correction techniques based on jet, lepton, calorimeter isolation, pileup, underlying effect, and tunings based on specific physics channels were developed and optimized. To fully exploit the correlation between the Emiss T and various physics final states, we developed a physics model of Emiss T by factorizing the jet system from related detector effects based on QCD di-jet events, and then extended this model to a general multiple jet system. We used the model to evaluate the jet energy calibration on Emiss T and the influence of various detector effects on the Emiss T . Our study provided a fundamental framework to systematically understand, analyze, and evaluate Emiss T related quantities. We performed a feasibility study on a direct Higgs mass (mH) reconstruction for the low mass region (120 < mH < 250 GeV/c 2 ) by explicitly reconstructing hadronic and leptonic W from the Higgs boson decay using `νjj final states. A large number of background processes were simulated and studied. Various techniques were developed (lepton isolation, forward jet tagging, central jet selection, hadronic and leptonic W reconstruction, and Emiss T selection) to increase the significance of the signal events. For an integrated luminosity of 30 fb−1 , a 5σ discovery for 160 < mH < 180 GeV/c 2 can be achieved. We developed experimental data analysis methods to identify the existence of Higgs boson without needing accurate knowledge of the selection efficiency. Two main systematic issues were discussed: jet energy scale and initial (final) state radiation. The feasibility of the reconstruction paves the way of the H → W+W− → `νjj as an effective channel for the Higgs boson search via VBF in the most interested region of 120 < mH < 220 GeV/c 2 , while this channel was mainly considered for high mass Higgs boson search before

Search for Standard Model Higgs Boson via Vector Boson Fusion in the H→W+W−→l pmνjjH \to W^{+}W^{-} \to l^{\ pm} \nu jj with 120<mH<250GeV/c2120 \lt m_{H} \lt 250 GeV/c^ {2}

The feasibility of discovering the Standard Model Higgs boson is investigated via Vector Boson Fusion in rm H to W^ + W^ - to rm ell nu jj channel. A comprehensive strategy of Higgs mass (rm m_H) reconstruction is developed using detector jets, lepton and missing transverse energy (rm E_T^miss). At an integrated luminosity of 30 rm fb^-1, a 5 rm sigma discovery can be achieved for rm 140 < m_H < 200 rm GeV/c^2. Several important techniques including forward jet tagging, central jet selection, hadronic and leptonic W reconstruction, rm E_T^miss selection, lepton-W correlation and lepton isolation, are optimized to increase the signal to background ratio. Data driven analysis methods are developed to further identify the experimental signature of the signal in addition to the reconstructed Higgs mass peak and reduce the effect of a variety of detector systematic uncertainties